Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Cascais (57% of total searches to Sintra-Cascais Natural Park). The next most popular destinations are Sintra (39%) and Colares (2%). Searches for hotels in Mafra (2%) are also popular.
KAYAK users have found double rooms in Sintra-Cascais Natural Park for as cheap as $22 (Cascais) in the last 3 days. The average price is $198.